Lesson Title:Convection Currents and the Mantle - Part 2
State Standards: GLEs/GSEs
National Standards:
Context of Lesson:
This is the second class of the second section of the Plate Tectonics unit Plan. The students will further investigate the concept of convection byconductingexperiments based on density and heat. They will then apply this new concept into their expanding model of the Earth which is be manifested in the incorporation of the concepts, data, and reflections into their ongoing Science Ring project.
This second class will cover the application of the skill in calculating density in different objects as well as investigating the significance of density in liquids and how liquids of different densities interact. We will also apply this knowledge into our model of the Earth.
Prerequisite Knowledge
That heat applied to a substance makes molecules move faster and space between molecules is increased.
Materials
Clear plastic cups, food coloring and dropper, vegetable oil.
1cm³ pieces of wood, metal, & 27cm³ pieces of styrofoam, scale, rulers & calculators.
Bucket of cold water in center of cleared space where Density Cube is marked off. Objectives: Students will:
Calculate density of various substances.
Describe how temperature change affects density.
Describe the concept of convection: (how fluids with varying densities interact).
Apply the concept of convection into their Earth model.
Instruction:
Opening:(5 minutes)
Have the following written on the board:
Quietly Share your answers to the homework with a neighbor. See if you have the same answers and fix any ones that are wrong.
As you collect their Density Homework remind them that their ability to calculate density is important and that this class will take this concept of density and apply it to their model of Earth, and that is what this section is all about. Today, we will investigate how heat affects the density of liquids and how liquids of different densities interact. Finally we will see if we can apply this knowledge of heat and density into an understanding of a key concept of our Earth model called convection. Ask if any students knows what convection is.
Engagement:(45 minutes)
Break the class into groups of 4 Activity 1 Pass out 1cm³ pieces of wood, metal, & 27cm³ pieces of styrofoam and a lab worksheet.labsheetdensity Ask the students for a prediction on which of these three objects will float if placed in the bucket. Field questions and when a student says the heavier object will sink interject with prompt, Heavier than WHAT? Tell them that scientists have already figured out that when an object weighs more than than an equal volume of the substance it is in than it will float.
Remind them that they already have a measurement which gives the weight of an object for a given volume. It was what they did yesterday and on their homework. DENSITY.
Have each group independently figure out the density of the three objects and note the data on their labsheet. Inform them that the accepted density of water is 1 gram / cm³ and they are to fill their lab sheet with that data.
Once all teams have completed, have a designated student from each group place the three objects into the bucket and report back to their group and note their findings. Lead the class in a discussion summarizing their findings that any less dense object will float in a more dense fluid. Tell them that this applies to liquids within liquids also.
Activity 2 Pass out 2 clear plastic cups. Have the students pour water into 1 cup till 1/3 filled. Add food to water coloring. Then have students pour 1/4 cup of clear vegetable oil into the cup.
Ask the students to choose the less dense liquid based on their observations. Ask a responder to explain his/her reasoning. Ask for any dissenters, and their reasonings for not agreeing.
Activity 3 Say; Before we go further, we must also look at how the different temperatures inside the Earth can affect the density of the material.
Let's use our Density Cube to illustrate how heat (measured by temperature) affects density. I need 7 student molecules to enter the Density Cube as we did yesterday. Let's assume we are measuring the density of the mantle at a temperature of 870ºC. Assume that each students weighs 100lbs. What is the density of our mantle at 870ºC? (answer = 700lbs ÷ 27yards³ = 26 lbs/yards³. Write this on board. I now see where you got the "27" in the previous lesson. :-) You should only calculate density in the appropriate units. It is interesting that you had the students "practice" calculating densities in unit of g/cm^3 and now you're not using those units.
Have the students walk around the Cube slowly, occassionally bumping into each other. Remind them that the temperature reflects the speed at which the 7 student molecules are moving and at that temperature (870ºC) they have just enough space to move around in the box. Are students modeling a liquid? If so, they should be pretty close together, right? Tell them if we add heat to the molecules they will move faster and record an increase temperature of 1000ºC. This increased movement will make collision greater and the molecules will move farther apart. Have the "student molecules" illustrate this increased activity in the Density Cube and say that now only 6 student molecules can now be in that space. Have 1 student stand outside the box.
Ask the students to figure out the new density of our box at 1000ºC. Answer 600lbs ÷ 27yards³ = 22.2 lbs/yards³ This demonstration could get ugly if students are pushing each other during collisions. How will you control for this.
A simulation that reinforces this point can be found here: http://phet.colorado.edu/simulations/sims.php?sim=States_of_Matter On the board write down that information next to the density at 1000ºC and ask the students which part of the mantle is less dense. Then ask which will move (float) upwards.
What about the Ring of Science? Do these results warrant a knowledge card?
Closure:(5 Minutes)
Ask the class for evidence that they have accomplished the following ,answering any questions or addressing any misconceptions;
Calculate density of various substances.
Describe how temperature change affects density.
Describe the concept of convection: (how fluids with varying densities interact).
Apply the concept of convection into their Earth model.
Tell them that tomorrow they will discuss the concept of convection and document their newly acquired knowledge into their Science Ring about the Earth.
Assessment:
Formative assessment
During the first two student centered activities circulate and probe for understanding during both activities, especially as the students complete their lab and fillout their density lab worksheet as a group. Provide behavior specific positive reinforcement for good work and specific redirection for misunderstanding throughout both activities.
Summative assessment
Homework - Density Worksheet will be included as part of their homework grade.
Lesson Title:Convection Currents and the Mantle - Part 2
State Standards: GLEs/GSEs
National Standards:
Context of Lesson:
This is the second class of the second section of the Plate Tectonics unit Plan. The students will further investigate the concept of convection by conducting experiments based on density and heat. They will then apply this new concept into their expanding model of the Earth which is be manifested in the incorporation of the concepts, data, and reflections into their ongoing Science Ring project.This second class will cover the application of the skill in calculating density in different objects as well as investigating the significance of density in liquids and how liquids of different densities interact. We will also apply this knowledge into our model of the Earth.
Prerequisite Knowledge
That heat applied to a substance makes molecules move faster and space between molecules is increased.Materials
Clear plastic cups, food coloring and dropper, vegetable oil.1cm³ pieces of wood, metal, & 27cm³ pieces of styrofoam, scale, rulers & calculators.
Bucket of cold water in center of cleared space where Density Cube is marked off.
Objectives: Students will:
Instruction:
Opening:(5 minutes)
Have the following written on the board:Quietly Share your answers to the homework with a neighbor. See if you have the same answers and fix any ones that are wrong.
As you collect their Density Homework remind them that their ability to calculate density is important and that this class will take this concept of density and apply it to their model of Earth, and that is what this section is all about. Today, we will investigate how heat affects the density of liquids and how liquids of different densities interact. Finally we will see if we can apply this knowledge of heat and density into an understanding of a key concept of our Earth model called convection. Ask if any students knows what convection is.
Engagement:(45 minutes)
Break the class into groups of 4Activity 1 Pass out 1cm³ pieces of wood, metal, & 27cm³ pieces of styrofoam and a lab worksheet.labsheetdensity Ask the students for a prediction on which of these three objects will float if placed in the bucket. Field questions and when a student says the heavier object will sink interject with prompt, Heavier than WHAT? Tell them that scientists have already figured out that when an object weighs more than than an equal volume of the substance it is in than it will float.
Remind them that they already have a measurement which gives the weight of an object for a given volume. It was what they did yesterday and on their homework. DENSITY.
Have each group independently figure out the density of the three objects and note the data on their labsheet. Inform them that the accepted density of water is 1 gram / cm³ and they are to fill their lab sheet with that data.
Once all teams have completed, have a designated student from each group place the three objects into the bucket and report back to their group and note their findings. Lead the class in a discussion summarizing their findings that any less dense object will float in a more dense fluid. Tell them that this applies to liquids within liquids also.
Activity 2 Pass out 2 clear plastic cups. Have the students pour water into 1 cup till 1/3 filled. Add food to water coloring. Then have students pour 1/4 cup of clear vegetable oil into the cup.
Ask the students to choose the less dense liquid based on their observations. Ask a responder to explain his/her reasoning. Ask for any dissenters, and their reasonings for not agreeing.
Activity 3 Say; Before we go further, we must also look at how the different temperatures inside the Earth can affect the density of the material.
Let's use our Density Cube to illustrate how heat (measured by temperature) affects density. I need 7 student molecules to enter the Density Cube as we did yesterday. Let's assume we are measuring the density of the mantle at a temperature of 870ºC. Assume that each students weighs 100lbs. What is the density of our mantle at 870ºC? (answer = 700lbs ÷ 27yards³ = 26 lbs/yards³. Write this on board. I now see where you got the "27" in the previous lesson. :-) You should only calculate density in the appropriate units. It is interesting that you had the students "practice" calculating densities in unit of g/cm^3 and now you're not using those units.
Have the students walk around the Cube slowly, occassionally bumping into each other. Remind them that the temperature reflects the speed at which the 7 student molecules are moving and at that temperature (870ºC) they have just enough space to move around in the box. Are students modeling a liquid? If so, they should be pretty close together, right? Tell them if we add heat to the molecules they will move faster and record an increase temperature of 1000ºC. This increased movement will make collision greater and the molecules will move farther apart. Have the "student molecules" illustrate this increased activity in the Density Cube and say that now only 6 student molecules can now be in that space. Have 1 student stand outside the box.
Ask the students to figure out the new density of our box at 1000ºC. Answer 600lbs ÷ 27yards³ = 22.2 lbs/yards³ This demonstration could get ugly if students are pushing each other during collisions. How will you control for this.
A simulation that reinforces this point can be found here: http://phet.colorado.edu/simulations/sims.php?sim=States_of_Matter
On the board write down that information next to the density at 1000ºC and ask the students which part of the mantle is less dense. Then ask which will move (float) upwards.
What about the Ring of Science? Do these results warrant a knowledge card?
Closure:(5 Minutes)
Ask the class for evidence that they have accomplished the following ,answering any questions or addressing any misconceptions;- Calculate density of various substances.
- Describe how temperature change affects density.
- Describe the concept of convection: (how fluids with varying densities interact).
- Apply the concept of convection into their Earth model.
Tell them that tomorrow they will discuss the concept of convection and document their newly acquired knowledge into their Science Ring about the Earth.Assessment:
Formative assessmentDuring the first two student centered activities circulate and probe for understanding during both activities, especially as the students complete their lab and fillout their density lab worksheet as a group. Provide behavior specific positive reinforcement for good work and specific redirection for misunderstanding throughout both activities.
Summative assessment
Homework - Density Worksheet will be included as part of their homework grade.
Reflections
(only done after lesson is enacted)Student Work Sample 1 – Approaching Proficiency:
Student Work Sample 2 – Proficient:
Student Work Sample 3 – Exceeds Proficiency: